Traditionally, washes for components of lithographic or paste ink printing apparatus have been based on organic solvent mixtures having minor amounts of non-solvent ingredients incorporated therein. These organic solvent mixtures are completely or nearly completely volatile, with a volatile organic compounds (V.O.C.) into the atmosphere. Such conventional washes rely upon chemical solvation to remove ink from printing press components.
Currently, blanket and roller washes for lithographic presses consist primarily of hydrocarbon mixtures of both aromatic and aliphatic compounds, with the possible addition of smaller quantities of chlorinated hydrocarbons, ketones, alcohols, amides, esters, surfactants or glycol ethers. All of these materials are classified as volatiles, for purposes of determining V.O.C. for air pollution standards, with the exception of chlorinated hydrocarbons and surfactants. These hydrocarbon mixtures are either flammable or combustible, and will undesirably swell rubber rollers and blankets to some extent. In addition, these conventional hydrocarbon mixtures may be irritating or corrosive to the skin and other body tissues.
Other types of blanket and roller washes for lithographic presses have also been proposed. For example, soap/solvent combinations have been suggested; however, such soap/solvent combinations have an undesirably high level of highly volatile V.O.C.'s. In addition, blanket and roller washes containing water and non-petroleum solvents have been proposed. However, although the water/non-petroleum solvent washes represent an attempt at increasing the flash point and decreasing the V.O.C. of a wash by the addition of water, such water/non-petroleum solvent washes have proven to be unsatisfactory.
Therefore, it is an object of the present invention to provide a blanket and roller wash for removing inks, particularly oleophylic or oleoresinous paste ink, from blankets and roller trains on a press, which blanket and roller wash does not suffer from the disadvantages of prior washes.
Another object of the present invention is to provide a blanket and roller wash having a very low, substantially 0%, emission of its volatile organic content.
It is yet another object of the present invention to provide a blanket and roller wash which removes ink from blankets and roller trains on a printing press by diluency and detergency rather than solvation.
Still another object of the present invention is to provide a blanket and roller wash which will not swell rubber blankets and rollers.
Still a further object of the present invention is to provide a blanket and roller wash which is not corrosive or irritating to the skin or other body tissues.
Finally, it is an object of the present invention to provide improved methods of removing ink from blankets and roller trains of a printing press.
These and other objects of the present invention will be further understood by reference to the following description and examples.